This invention is directed to tools to facilitate assembly and disassembly of various mechanical devices in which components are held together by retainer or snap-rings, and, more particularly, to a single tool with jaw members specifically configured and operated to easily access the free ends of both interior and exterior snap-rings for installation and removal in locations not easily accessible.
Retaining or snap-rings are either xe2x80x9cinternalxe2x80x9d or xe2x80x9cexternalxe2x80x9d. The internal type of snap-ring is used to retain elements such as bearings or shafts within a bore. A snap-ring extends circumferentially between a pair of free ends which have apertures to receive tips of the tool. The force applied by the tool either spreads the free ends to expand the ring or moves the free ends together to contract the ring. In order to install the ring in a bore it is contracted to allow it to pass into the bore, and then allowed to expand for engagement with an internal groove formed around the bore. The external type of retaining ring is used to retain elements such as bearings, gears or pulleys on shafts. An external ring normally engages an annular groove formed in the outer surface of a shaft to inhibit axial movement of an element mounted on the shaft. An external ring is installed by expanding the ring until its internal diameter is greater than the shaft. The tool is generally necessary for installing the snap-ring in and removing the snap-ring from either internal or external grooves. In addition, the expanding or contracting of the snap-ring must be maintained until the installation in the internal or external groove is complete. This may be difficult if access to the groove is restricted.
Snap-ring tools of the industry for installing and removing snap-rings are typically made as pliers comprising two jaws made integral with two handles pivoted together in the center. These single purpose pliers are each intended to remove of install one type of ring only. A mechanic is required to have snap-ring pliers for both internal and external snap-rings. A typical snap-ring tool is disclosed in U.S. Pat. No. 5,943,754. The tips of the jaws of ""754 and the angle of the tips with respect to the jaws are unique to free ends of the snap-ring.
It is desirable to effect movement of the tips in the jaws outwardly to expand the snap-ring, and, at other times, it is desirable to effect the movement of the tips in the jaws inwardly to contract the snap-ring. A conventional snap-ring pincher tool in common use at the present for internal use comprises two jaws and two handles pivoted together at the center to operate as pliers. The jaws have tips at one end to engage free end apertures of the snap-ring. When not in use, the handles and the jaws with tips are pushed open by a spring. The jaws are closed by gripping the handles to install an internal snap-ring. A conventional snap-ring expander comprises two jaws and two handles pivoted together at the center to again operate as pliers. However, when the handles are pushed open by a spring, the jaws with tips are closed. Gripping the handles opens the jaws to install an external snap-ring. Conventional pliers, which can be converted from a pincher tool to an expander tool for either internal or external snap-rings, are disclosed in U.S. Pat. Nos.: 4,793,224 and 6,257,105. Both ""224 and ""105 include removable jaws with tips that can be alternately attached to the pivoting handles to provide either the pincher or the expander tool. The operation of these tools requires continuous gripping of the handles to maintain the snap-ring in a contracted or expanded configuration. In addition , as with any snap-ring pliers, the tips are not only displaced one from the other, but they are also rotated about a pivotal axis of the pliers. This rotation must be provided for by the tips themselves or the apertures and /or cutouts in the free ends of the snap-rings.
Manipulation between internal and external tool operating positions of a snap-ring tool has been disclosed in U.S. Pat. Nos.: 4,625,379; 5,065,650; 5,174,177; and 6,378,403. In the ""177 and ""650 patents a pair of levers includes a boss portion interconnecting the handles with the jaw portions for manipulation between internal and external tool operating positions. Movement between the internal and external positions is provided by a rotatable eccentric knob. The ""379 patent includes latch members which are switched so that the handles are coupled to a different jaws depending on the location of the latch members. In the ""403 patent the pliers convert from external to internal use by operating a pair of pins disposed in the jaws. All of the patents require an adjustment of the tool to change the movement of the tips from internal to external snap-rings. Once again, the operation of these tools requires continuous gripping of the handles to maintain the snap-ring in a contracted or expanded configuration, and the tips are not only displaced one from the other, but they are also rotated about a pivotal axis of the pliers.
The need remains to provide a single snap-ring tool that can be operated for internal and external applied rings without adjusting or modifying the tool. Another need is to have a snap-ring tool that can maintain the snap ring in a expanded or contracted configuration without continuously gripping the tool. Many applications of snap-rings involve difficult areas to access. The more freedom in the ability to manipulate the tool the easier the installation or removal of the snap-ring becomes. A further need is to have the tips move with respect to one another without a rotational displacement. That is, the jaws holding the tips must linearly translate from one another to eliminate any rotation.
Accordingly, an object of the present invention is to provide a single universal tool that can function equally well with externally or internally applied retainer or snap-rings without the need for any adjustment.
Another object of the present invention is to provide a jaw positioning assembly configured to move the jaws of the universal tool so they translate from one another without rotation. A further aspect of the translating jaws is to provide for symmetrical displacement of the jaws with respect to the handle centerline
A further object of the present invention is to provide a universal snap-ring tool which can expand or contract a snap-ring and hold the expanded or contracted configuration without continuously gripping the handle of the tool to provide the best orientation of the tool to install or remove the snap-ring.
The above objectives are accomplished according to the present invention by providing a retaining or snap-ring tool that can be universally used with either internally or externally applied snap-rings. The universal tool has a pair of jaws that include a tip to interface with the free ends of the snap-ring to either expand or contract the ring. A jaw positioning device moves the jaws apart, unlike the snap-ring pliers known in the industry. A single handle is connected to a first jaw and the second jaw is supported from the first jaw by the positioning device. A positioning wheel of the positioning device is rotated to move the jaws carrying the tips to any desired position to operate the snap-ring. The handle can be released without changing the deformation of the snap-ring.
In one embodiment of the invention, a universal tool for fitting and removing snap-rings with both external and internal operating movement is provided. The universal tool comprises a jaw assembly connected to a handle assembly. First and second jaws of the jaw assembly each have upper and lower ends. The first and second jaws are disposed to be linearly separated a uniform distance one from the other. A pair of tips each disposed at a respective one of said lower ends of the first and second jaws to engage the snap-rings and alter their circumferential dimensions. A single handle of the handle assembly is connected to said upper end of the first jaw for holding the pair of jaws in one hand with the tips in a position to engage a respective snap-ring. A jaw positioning device of the jaw assembly is for supporting the second jaw from the first jaw the uniform distance. Operating the jaw positioning device linearly displaces the pair of jaws with tips one from the other. The jaw positioning device comprises a pair of guide pins attached to one of the jaws and extends through guide apertures of the other jaw for maintaining a uniform distance between the first and second jaws. At least one threaded shaft interconnects the first with the second jaw so that rotating the threaded shaft in one direction moves the jaws closer together and and rotating the threaded shaft in the other direction moves the jaws further apart.
In another embodiment of the present invention, first and second jaws of the jaw assembly each have, once again, an upper end and a lower end. However, the first and second jaws are disposed to be rotationally separated one from the other. A jaw pivot pin connects the upper end of the second jaw to the first jaw so that the second jaw is rotationally supported by the first jaw. The jaw positioning device comprises a pair of shaft pins to receive a pair of the threaded shafts so that rotating the threaded shafts in one direction decreases the angle between the first and second jaws and rotating the threaded shafts in the other direction increases the angle between the first and second jaws
In one aspect of the invention the lower ends of the first and second jaws each have an aperture so that tips at the lower ends of the jaws are removable to be replaced by a alternate pair of tips. Additional pairs of tips are provided to replace the pair of tips for different snap-ring types.
In another aspect of the present invention, the handle is made with a cavity to accept the folding jaw assembly realized by providing a pivot pin connection between the handle assembly and the jaw assembly. In a further aspect the handle assembly can be made with a storage compartment for extra snap-rings, tips and the like.
In yet another embodiment of the invention, first and second jaws of the jaw assembly each have first and second ends with the jaws disposed to be linearly and symmetrically separated a uniform distance one from the other with respect to a central tool axis. A glide portion supports the first and second jaws in a position to be symmetrically displaced apart with respect to a central tool axis. A single handle of the handle assembly is affixed to a support arm of the glide portion for holding the guide portion in one hand to support said pair of jaws. The pair of tips are each inserted in and held by said first ends of said first and second jaws to engage said snap-rings and alter their circumferential dimensions. The pair of tips are removable so that an alternate pair of tips can replace the pair of tips. A glide portion supports the first and second jaws in a position to be symmetrically displaced apart with respect to a central tool axis. A single handle of the handle assembly is affixed to the glide portion for holding the glide portion to support the pair of jaws with the pair of tips in a position to engage the snap-ring. A jaw positioning device of the jaw assembly displaces said first jaw from said second jaw the uniform distance. Therefore, operating said jaw positioning device linearly displaces the pair of jaws with tips one from the other in a symmetrical offset arrangement with respect to the central tool axis. The glide portion includes a support arm affixed at one end to the single handle, a glide slot built integral with the other end of the support arm for supporting the first and second jaws, a jaw pin at the second end of each jaw for slidably connecting the first and second jaws to the glide portion and a wheel centering tab of the glide portion to maintain the first and second jaws in the symmetrical offset arrangement. A slotted positioning wheel is made integral with a pair of threaded shafts for the user to rotate the threaded shafts to change the distance between the first and second jaws. The wheel centering tab meshes with a slot in the slotted positioning wheel.